The 2012 National Science Education Standards published by the National Research Council call for an integrative, research-based curriculum in science that incorporates high quality laboratory activities that help students learn to investigate, to construct scientific assertions, and to justify those assertions. Yet in their own U.S. Lab Report, the NRC indicates that the majority of high school students participate in science laboratory experiences that are poorly developed and lack clear learning goals. Currently, lab activities are inhibited by many factors, including limited funds and resources, large class sizes, and inadequate teacher training. Moreover, high school science labs are often boring, and use the cookbook approach. Over the past 15 years we have developed and assessed the efficacy of substance abuse-focused modules on learning in high school biology and chemistry. Topics about drugs and alcohol are highly relevant and interesting to high school students. In our most recent study, we developed a lab activity that engages students virtually (www.rise.duke.edu/SEEK). The widespread use of this resource by teachers in our study led to the development of this proposal. We will develop a web-based platform (REX) for educators and their students to engage in virtual laboratory experiments performed by real scientists. Our overall goals of this project are to 1) provide teachers with a rich resource that can be used to integrate inquiry-based virtual lab experiences into the classroom , 2) increase high school student mastery of basic biology and chemistry principles and 3) increase student interest in science and science careers (especially in areas of substance abuse). To achieve these goals, we have 4 specific aims: 1) develop REX (Real Experiments), an interactive web-based platform, to conduct lab experiments online that real scientists perform in areas of substance abuse, 2) design 6 pharmacology-oriented experiments focused in areas of drug and alcohol abuse to populate REX. We will incorporate an interactive algorithm that allows students to participate in the design of their own experiment, analyze data generated by real scientists, interpret results, and reflect on their findings and next steps, 3) field-test REX in10 high school science classrooms (~ 1000 students) in the Durham, NC school district, which comprises a large population of underrepresented minorities, and 4) perform several types of assessments that test the effect of REX on mastery of basic biology and chemistry principles and determine the effect of REX on interest in science and science careers (the study will be controlled). Finally we will conduct an evaluation of the usability of REX by teachers before dissemination publically. We expect that our engaging online resource will be especially useful to teachers and schools without money, training, or infrastructure to conduct laboratory experiments.